Mechanical Property Characterization of Aligned Plant Yarn Reinforced Thermoset Matrix Composites Manufactured via Vacuum Infusion

This article evaluates the mechanical properties of vacuum-infused unidirectional plant fiber composites (PFRPs), composing of bast fiber yarns and thermoset matrices. PFRPs are found to have lower fiber volume fractions than E-glass composites (GFRPs). Apart from the expected (30–40%) lower density of PFRPs, they have 60–80% lower tensile strength, 30–60% lower tensile stiffness, 5–10 times lower impact strength, and 20–30% lower interlaminar shear strength than GFRPs. Importantly, critical fiber lengths are of the same order (0.2–0.5 mm). Composites reinforced with flax rovings exhibit exceptional fiber tensile modulus of 65–75 GPa and fiber tensile strength of about 800 MPa.